Adjustable support for electric lamps



May 3, 1938. H. A. slTocK ET' AL ADJUSTABLE SUPPORT FOR ELECTRIC LAMPS Filed Feb. 5, 1957 Patented May 3, 1938 2,116,050

UNITED STATES PATENT OFFICE Y vADJUS'IABLE v-snrrolt'r Foa ELECTRIC f I LAMPS Hubert Arthur Stock and Archibald Joseph Wilmot, Peterborough, England Application `February ,5, 1937, serial No. 124,318 `In Great Britain February 14, 1936 3' Claims. (cl. 285-1) This invention relates to adjustable holders 01 number of tubular arms may be embodied in the supports for electric lamps andhas for its object holder, one end of a series of such jointed arms to provide an improved construction for this purbeing connected to a suitable base, or to a wall pose which may be readily kattached to, or supplug, and the other end to the lamp holder proper.

5 ported on or by, a desk, wall, ceiling, machine Further, by including swivel joints where I'e- 5 or other xture, in such manner that the lamp spective swivelling axes are disposedin different may be directed to throw a beam of light in any planes, the invention renders possible the conrequired direction. struction of an extensible electric lamp holder The invention makes use of mechanical swivel or arm that can be readily adjusted in any dejoints which were known prior to this invention, sired position Vto throw a beam of light wherever 10 incorporating electric contacts which provide for required within the range of the arm.

a continuous electrical connection through the In order that the invention may be clearly joint between electric conductors on opposite sides understood and readily carried into practice, it of the joint. will now be more particularly described with With the above and other objects and advanreference to the accompanying drawing illuo- 15 tages in View, as will appear from the following trating how it may be carried into practice. In description an adjustable holder or support for the drawing:-

electric lamps according to the invention com- Figure 1 is an elevation of one construction ci prises a plurality of tubular arms connected totable or bench lamp according to the invention;

gether, and to a lamp holder and a base member, Figure 2 shows a modied .construction of table Z0 by hollow swivel joints comprising cylindrical or bench lamp with the lamp itself swivelled box-like inter-engaging male and female cone for movement in a plane at right angles to that joint members permitting 360 relative angular permitted by the other swivel joints, and movement, said lamp holder being electrically Figure 3 is a sectional view to an enlarged scale connected to the base member by discontinuous of a swivel connecting joint according tothe 25 conductors contained in the hollow arms, and invention. rotary electrical connectors in said hollow swivel Referring to Figures l and 2, the lamp comjoints. prises a supporting base member l within which According to a further feature of the invenis mounted a rotatable member la adapted t0 so tion the rotary electrical connectors comprise an rotate in a plane parallel to the bottom of the insulating plate carrying concentric contact rings base and to which is articulated at 2 a tubular in one joint member, and an insulating plate arm 3 which is in turn articulated at 4 to ancarrying spring pressed contact members disother tubular arm 5. The opposite end of the posed at radii corresponding to said Contact rings tubular arm 5 is articulated at 6 to a bracket in the other joint member, said spring pressed carrying the socket 9 of an electric lamp I0. 35 contacts pressing on said contact rings when the In the case of Figure l the lamp socket 9 is members of the joint are fastened together in in xedrelation to the bracket 1, but in the case inter-engagement by a PVO Dill of Figure 2 the lamp socket 9 is articulated at 8 Preffrably the adjustable holder is built .up to the bracket 1. The axes of articulation at 2,

from mterchaqngeable tubular members havmg 4 and 6 are parallel to one another, so that the 40 female cone joint members at one end and correbracket 1 (and lamp lo in the ,case of Figure l) spondmg male Cone. 301m members .at the other is angularly adjustable only in a plane at right end Whst 1t may Include a plurahty of swlvel angles to the said axes of articulation In the joints whose respective swivelling axes are dis- Case of Figure 2 however the axis of'articula 46 polsg'tlllenrrrllite Ielrillnsdiment of the invention @on at 8 is at right angles' to th? axis 0f 311101112? 45 hereinafter described the hollow swivel joint non at 2 4 and as Whlch peflmts the lamp if) t0 members are provided with tube receiving sockets be angularly adylusted at 8 f1 a' plane at Hght directed laterally in relation to the swivelling angles '00 the adJuStment Delmltted by the articu- 50 axis of the joint, whilst the pivot pin securing lftlOnS 2, 4 and 5- 50 the joint members together passes through, and 'I'he electric leads Il enter the base member I, is screw threaded to receive a nut external to one and are connected to the lamp socket 9 through oiv the joint members, by adjustment of which the articulations 2, 4, 6 (and 8) in such manner the stiness of the swivel joint may be varied. that electrical continuity is obtained nothwith- In carrying the invention into practice any standing movement ofthe articulations and with- 55 out twisting the electrical conductors between the base member I and the lamp socket 9.

This result is obtained by constructing the swivel joints 2, 4, B (and 8) in the manner illustrated in principle by Figure 3, which is a sectional view of the swivel joint at 4, between the arms 3 and 5 of the lamp.

Referring now to Figure 3, the swivel connecting joint comprises a pair of interengaged coaxial socket members I3, I5, which are each of substantially cylindrical box like form. The Wall of the socket member I3 is extended to form a conically recessed female portion I4 which reoeives therein the male portion I5 formed by the coned outer wall of the socket member I6. The two socket members are held together by an axial pivot pin I8 screwed into the socket mem ber I5, and a nut I9 bearing against the outside wall of the socket member I3.

The engaging male and female portions I4, I5 of the socket members I3 and I6 are offset from the axes of the tubular arms 3 and 5 to which they are respectively connected by the laterally projecting sockets I2 and I'I, so that the two arms 3 and 5 can move angularly in relation to one another in parallel spaced planes.

In the socket member I3 is mounted an insulating disc 20 having holes in which slide radially spaced contact plungers 2I, on, the inner ends of which bear leaf springs 22 fastened to the disc 2li by screws 23 to which the electrical conductors 24 are connected.

In the mouth of the spigot I5 of socket member I6 is mounted another insulating disc 25 in the surface of which are inset a pair of concentric metal contact rings 26 which are located to make contact with the two radially spaced plungers 2|. The contact rings 26 are connected to the electrical conductors 2'I which pass through the tube 5.

A spring or other non-rotatable washer 28 may be provided under the nut I9 to enable the nut I9 to be tightened up to give any desired degree of stiinessvof the swivel joint. Y

By the above construction it will be appreciated that a swivel joint is established, which not only functions mechanically, as such, to permit any desired angular adjustment of the members connected to the joint from 0 to 360, but also functions in an equivalent manner as regards the electrical conductors carried by the connecting members, to the extent that the said conductors are electrically connected through the swivel joint in all positions of adjustment of the joint. l

It will be obvious that although Figure 3 illustrates a specic construction for the articulation 4, suitably modied constructions operating on the same principle may be employed for the articulations at 2, 6 and 8, the supply leads II being connected to the conductors 24 through the ring and plunger contacts of the swivel joint 2, and the conductors 21 being connected to the conductors in the bracket 1 through the ring and plunger contacts of the swivel joint 6.

What we claim is:-

1. An extensible bracket for electric lamps and like appliances, including tubular arms connected for relative swiveling movement, a lamp socket bracket connected for swiveling movement to the free terminal of one of said arms, electric conductors wholly concealed within the arms, and means at the swiveling connection of each arm to provide uninterrupted electrical connections for the conductors throughout the length of the bracket, said means preventing any strain or twisting on the electrical conductors during any possible relative swiveling movement of the arms or lamp socket bracket.

2. A construction as defined in claim l, wherein said means includes contacting members each connected to one end of the meeting arms to maintain electrical continuity of the conductors in all relative positions of the arms.

3. A construction as defined in claim l, wherein the swiveling connections between the arms and the contacting members are supported on a common pivot.

HUBERT ARTHUR STOCK. ARCHIBALD JOSEPH WILMOI. 

